This invention relates to an IC card for use in electronic computers and other devices of this kind, particularly a shuttered card-edge type IC card and a connector for connecting the card.
An IC card has been used for supplying informations to be inputted into or writing informations to be outputted from electronic computers, particularly console units thereof or small electronic computers into which the IC card is inserted. In handling the IC card, there is a risk of memorized informations being broken down if a user's hand touches a connecting terminal portion of the card.
In order to avoid such an accident, an IC card as shown in FIG. 1 has been widely used. This IC card has a memory portion coated with a coating 112 of a synthetic resin or the like except a connecting terminal portion 111. Moreover, the IC card is provided with a movable shutter 113 between the connecting terminal portion 111 and the coating 112 for covering the terminal portion 111.
With this arrangement, when this IC card is inserted a connector provided in an electronic computer or the like, operating pawls 114 provided on both sides of the shutter 113 are pushed rearward so as to expose the connecting terminal portion to establish a connection between the card and the connector. When this card is drawn from the connector, the shutter 13 is automatically returned by an action of a spring 115 provided between the shutter 113 and the coating 112 to cover the connecting terminal portion 111. The IC card shown in FIG. 1 is a typical one of this kind, which has generally 80-90 mm length, 50-60 mm width and 1.5-2.5 mm thickness.
The shuttered IC card of the prior art as above described is superior in prevention of dust because of the shutter covering the terminal portion except when being used. Moreover, the shutter somewhat serves as an electrostatic shield. However, such a shuttered IC card encountered the following problems to be solved.
(1) As the operating pawls 114 extend outwardly, there is a risk of the pawls unintentionally brought into contact with another member when it is being used or carried to open the shutter 113, resulting in an unexpected accident.
(2) The terminal portion 3 is arranged on only one side of the IC card, so that it cannot provide for the increased number of terminals due to the improvement of integrated degree. Accordingly, this IC card does not fulfil the requirement of providing with terminals as many as possible. Such a requirement has become acuter with the increase in memory capacity of IC cards.
(3) The shutter 21 is electrically independent from a circuit in the IC card, so that the shutter 21 is not necessarily at the same potential as the ground of the circuit in the IC card. Therefore, if the shutter is charged with static electricity for any reason, it may discharge to the circuit in the card, so that the circuit is often damaged.
(4) The IC card and the connector are electrically independent from each other before being connected, so that grounds of the connector and IC card are not necessarily at the same potential. In the event that they are at different potential, when the IC card is inserted into the connector, electromagnetic troubles often occur in either or both the IC card and electronic equipment on the side of the connector.